#include <iostream>
#include <vector>


int main()
{
    std::vector<int> v1;
    int i1;

    while(std::cin >> i1)
    {
        v1.push_back(i1);
    }
    // 输出每对相邻整数的和
    for(decltype(v1.size()) i = 0; i < v1.size() - 1; ++i)
    {
        std::cout << "sum is " << v1[i] + v1[i+1] << std::endl;
    }

    return 0;
}